A metering and mixing apparatus is disclosed in European Patent Application 10 196 972.3 of the applicant.
A similar metering and mixing apparatus for mixing a dental impression compound is already known from DE 3 233 366 A1. This device includes a stirring unit, designed as a disposable part, with a base body that has a mixing chamber with several feed channels opening separately into the mixing chamber for the components of the impression compound and an outlet opening for the mixed impression compound. The stirring unit also has a stirrer, arranged rotatably in the mixing chamber, which is driven by a driving device against which the stirring unit is held removably. The components of the impression compound are held in reservoir cylinders and are forced by pistons into the mixing chamber, and after mixing are forced out through the outlet opening into the impression tray. The speed of advance of the actuating drives of the pistons can be varied so that both the ratio of the piston advance speed, which determines the setting time of the impression compound and the overall advance or the duration of advance and thus the quantity of impression compound, can be controlled.
Reference is also made to EP 0 057 465 A2, WO 2011/025831 A1, US 2009/039113 A1, WO 2008/076941 A1 and EP 2 279 379 A1.